Fan Device

ABSTRACT

A fan device includes: a fan housing configured with a receiving space defined among opposite top and bottom walls, and a surrounding side wall; a fan impeller mounted in the receiving space, disposed adjacent to an air outlet in the top wall and operable to rotate about a central axis transverse to the top and bottom walls of the fan housing; and an air-guiding unit mounted fixedly in the receiving space and disposed adjacent to an air inlet in the bottom wall. The air-guiding unit includes a central connecting member disposed axially with the central axis, and a plurality of angularly spaced apart air-guiding blades interconnecting the central connecting member and the surrounding sidewall. An angular distance between each adjacent pair of the air-guiding blades is different from that of any other adjacent pair of the air-guiding blades.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Application No. 098143618,filed on Dec. 18, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a fan device, and more particularly to a fandevice capable of producing enhanced air pressure.

2. Description of the Related Art

In order to enhance air pressure, a stator impeller is applied to a fan.The stator impeller is mounted to a fan housing of the fan, and includesa plurality of angularly equidistant stator blades. An air-guidingchannel is formed between an adjacent pair of the stator blades. When afan impeller of the fan is driven to rotate, air flowing from the airinlet is guided by the stator impeller to flow toward the fan impellerthrough the air-guiding channels, thereby enhancing air pressureproduced by the fan. As a result, increased airflow amount can beattained. However, in such a configuration, greater acoustic noiseoccurs during rotation of the fan impeller at a speed within a certainspeed range.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a fan devicethat can produce enhanced air pressure and increased airflow amount withreduced acoustic noise.

According to the present invention, a fan device comprises:

a fan housing configured with a receiving space and having a bottom wallformed with an air inlet in spatial communication with the receivingspace, a top wall formed with an air outlet in spatial communicationwith the receiving space, and a surrounding side wall transverse to andinterconnecting the top and bottom walls, and cooperating with the topand bottom walls to define the receiving space thereamong;

a fan impeller mounted in the receiving space in the fan housing,disposed adjacent to the air outlet in the top wall of the fan housing,and operable to rotate about a central axis that is transverse to thetop and bottom walls of the fan housing; and

an air-guiding unit mounted fixedly in the receiving space in the fanhousing and disposed adjacent to the air inlet in the bottom wall of thefan housing, the air-guiding unit including a center connecting memberdisposed coaxially with the central axis, and a plurality of air-guidingblades angularly spaced apart from each other and interconnecting thecentral connecting member and the surrounding side wall of the fanhousing, an angular distance between each adjacent pair of theair-guiding blades being different from that of any other adjacent pairof the air-guiding blades.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiments with reference to the accompanying drawings, of which:

FIG. 1 is a schematic bottom view showing the first preferred embodimentof a fan device according to the present invention;

FIG. 2 is a perspective view showing the first preferred embodimentwithout a fan impeller;

FIG. 3 is a partly schematic sectional view showing the first preferredembodiment;

FIG. 4 is a plot illustrating experimental measurement results ofacoustic noise generated by the prior art and the first preferredembodiment;

FIG. 5 is a schematic top view showing the second preferred embodimentof a fan device according to the present invention without a fanimpeller;

FIG. 6 is a schematic top view showing a variation of the secondpreferred embodiment; and

FIG. 7 is a schematic top view showing the third preferred embodiment ofa fan device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail, it shouldbe noted that like elements are denoted by the same reference numeralsthroughout the disclosure.

Referring to FIGS. 1 to 3, the first preferred embodiment of a fandevice according to the present invention is shown to include a fanhousing 1, a fan impeller 2, and an air-guiding unit 3.

The fan housing 1 is configured with a receiving space 10, and has abottom wall 11, a top wall 12 and a surrounding side wall 13. The bottomwall 11 is formed with an air inlet 111 in spatial communication withthe receiving space 10. The top wall 12 is formed with an air outlet 121in spatial communication with the receiving space 10. The surroundingside wall 13 is transverse to and interconnects the top and bottom walls12, 11, and cooperates with the top and bottom walls 12, 11 to definethe receiving space 10 thereamong.

The fan impeller 2 is mounted in the receiving space 10 in the fanhousing 1, is disposed adjacent to the air outlet 121 in the top wall 12of the fan housing 1, and is operable to rotate about a central axis (X)that is transverse to the top and bottom walls 12, 11 of the fan housing1. In this embodiment, the fan impeller 2 includes a hub body 21, and aplurality of fan blades 22 extending outwardly and radially from the hubbody 21. In this embodiment, the fan blades 22 are angularlyequidistant.

The air-guiding unit 3 is mounted fixedly in the receiving space 10 inthe fan housing 1, and is disposed adjacent to the air inlet 111 in thebottom wall 11 of the fan housing 1. The air-guiding unit 3 includes acenter connecting member 31 disposed coaxially with the central axis(X), and a plurality of air-guiding blades angularly spaced apart fromeach other and interconnecting the central connecting member 31 and thesurrounding side wall 13 of the fan housing 1. An angular distance (θ)between each adjacent pair of the air-guiding blades 32 is differentfrom that of any other adjacent pair of the air-guiding blades 32. Inthis embodiment, the center connecting member 31 includes a circular capbody 312, and a tube body 311 extending integrally from the cap body 312toward the hub body 21 and disposed coaxially with the central axis (X).

In operation, when the fan impeller 2 is driven to rotate, air flowingfrom the air inlet 111 is guided by the air-guiding blades 32, and thenflows toward the air outlet 121, as indicated by solid-line arrows inFIG. 3.

In sum, due to the presence of the air-guiding unit 3, the fan device ofthe present invention can produce enhanced air pressure, therebyresulting in increased airflow amount. It is noted that, since theangular distances (θ) are different from each other, the fan device ofthe present invention generates reduced acoustic noise during operationas compared to the prior art, as shown in FIG. 4.

FIG. 5 illustrates the second preferred embodiment of a fan deviceaccording to this invention, which is a modification of the firstpreferred embodiment. Unlike the first preferred embodiment, theair-guiding unit 3′ further includes a plurality of auxiliaryair-guiding blades 33 extending inwardly and radially from thesurrounding side wall 13 of the fan housing toward the centralconnecting member 31. Each auxiliary air-guiding blade 33 is disposedbetween a corresponding adjacent pair of the air-guiding blades 32, andis spaced apart from the corresponding adjacent pair of the air-guidingblades 32 and the central connecting member 31. In this embodiment, theauxiliary air-guiding blades 33 have the same length.

FIG. 6 illustrates a variation of the second preferred embodiment,wherein each of the auxiliary air-guiding blades 33 of the air-guidingunit 3′ has a length different from that of any other one of theauxiliary air-guiding blades 33.

FIG. 7 illustrates the third preferred embodiment of a fan deviceaccording to this invention, which is a modification of the firstpreferred embodiment. Unlike the first preferred embodiment, an angulardistance (Φ) between each adjacent pair of the fan blades 22 isdifferent from that of any other adjacent pair of the fan blades 22.

While the present invention has been described in connection with whatare considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements includedwithin the spirit and scope of the broadest interpretation so as toencompass all such modifications and equivalent arrangements.

1. A fan device comprising: a fan housing configured with a receivingspace and having a bottom wall formed with an air inlet in spatialcommunication with said receiving space, a top wall formed with an airoutlet in spatial communication with said receiving space, and asurrounding side wall transverse to and interconnecting said top andbottom walls, and cooperating with said top and bottom walls to definesaid receiving space thereamong; a fan impeller mounted in saidreceiving space in said fan housing, disposed adjacent to said airoutlet in said top wall of said fan housing, and operable to rotateabout a central axis that is transverse to said top and bottom walls ofsaid fan housing; and an air-guiding unit mounted fixedly in saidreceiving space in said fan housing and disposed adjacent to said airinlet in said bottom wall of said fan housing, said air-guiding unitincluding a center connecting member disposed coaxially with the centralaxis, and a plurality of air-guiding blades angularly spaced apart fromeach other and interconnecting said central connecting member and saidsurrounding side wall of said fan housing, an angular distance betweeneach adjacent pair of said air-guiding blades being different from thatof any other adjacent pair of said air-guiding blades.
 2. The fan deviceas claimed in claim 1, wherein said air-guiding unit further includes aplurality of auxiliary air-guiding blades extending inwardly andradially from said surrounding side wall of said fan housing toward saidcentral connecting member, each of said auxiliary air-guiding bladesbeing disposed between a corresponding adjacent pair of said air-guidingblades and being spaced apart from the corresponding adjacent pair ofsaid air-guiding blades and said central connecting member.
 3. The fandevice as claimed in claim 2, wherein said auxiliary air-guiding bladesof said air-guiding unit have the same length.
 4. The fan device asclaimed in claim 2, wherein each of said auxiliary air-guiding blades ofsaid air-guiding unit has a length different from that of any other oneof said auxiliary air-guiding blades.
 5. The fan device as claimed inclaim 1, wherein said fan impeller includes: a hub body disposedcoaxially with the central axis; and a plurality of fan blades extendingoutwardly and radially from said hub body and angularly spaced apartfrom each other, an angular distance between each adjacent pair of saidfan blades being different from that of any other adjacent pair of saidfan blades.